Project Summary The proposal herein seeks to potentiate magnetic resonance imaging (MRI) using metamaterials in order to improve signal-to-noise ratio (SNR). MRI represents a cornerstone among the diagnostic tools available in modern healthcare. There has been an ongoing drive towards increasing static magnetic fields of MRI systems over the previous two decades in an effort to improve SNR, which may be translated into improved image resolution or decreasing scan times. However, the development of increasingly powerful magnetic fields incurs several trade-offs, including financial costs, safety concerns, and a host of image artifacts, among others. Alternative approaches that have also been developed in order to improve the overall SNR in MRI include the development of advanced RF coil technologies as well as the use of gadolinium-based contrast agents, both of which are routinely applied in the clinic. More recently, early efforts towards the application of metamaterials in MRI have been reported to enable improvements in SNR and efficiency through their capacity to interact with electromagnetic radiation in a novel fashion. While promising, the reported efforts applying MMs to MRI remain impractical and fail to realize the full potential of these unique materials. In this work, the use of metamaterials in MRI will be more fully developed, allowing for an engineered control of the RF electromagnetic field in MRI. Ultimately, this approach offers the potential to dramatically boost SNR without increasing the static magnetic field of the MRI system. In this work, metamaterials featuring metallic helices will be developed and optimized for operation at both 1.5T and 3.0T MRI platforms. Furthermore, tunable metamaterials based on the integration of a nonlinear material will be designed, yielding the capacity for RF enhancement only during the reception phase of the MRI signal acquisition. Following fabrication, the performance (SNR, image quality) of the metamaterials will be validated at both 1.5T and 3.0T MRI platforms using configurations specifically optimized towards spine imaging. The application of metamaterials in MRI has the potential to be rapidly translated towards the clinic, offering marked enhancements in SNR, image resolution, and scan efficiency, thereby enabling an evolution of the utility of this powerful diagnostic tool.